Sorry, but only you can solve this problem. Try to use JOINS (LEFT, RIGHT, INNER), rather then cross join. You need to define relationships between tables.
Probably, this part: WHERE BDD.BiltyNo <> BDC.BiltyNo is an element which generate wrong result. Try to change it as fallow: FROM ... AS BDC INNER JOIN ... AS BDD ON BDC.BiltyNo = BDD.BiltyNo.